code: def _unflattened_lookup(
      lookup: Dict, flat_key: str, delimiter: str = "/"
  ) -> Any:
      curr = lookup
      for k in flat_key.split(delimiter):
          try:
              curr = curr.get(k, {})
          except Exception:
              return None
      return curr
  
file_path: ray/release/ray_release/buildkite/filter.py
imports: import re
  import copy
  from collections import defaultdict
  from typing import List, Optional, Tuple, Dict, Any
  from ray_release.buildkite.settings import Frequency, get_frequency
  from ray_release.test import Test
  from ray_release.test_automation.state_machine import TestStateMachine
label_desc: Use image node_id 1 for calling a global function with example usage: _unflattened_lookup(lookup, flat_key, delimiter) and returns: curr, None